not to insult you or anything but if the cylinder misfire dcode come up constantly it mean it was either retarded a tooth or advanced a tooth the click noise your hearing is coming from the engine valves which could posibly mean a valve is bent
when you new timing belt was put on it could of not been timed correctly by the person who installed
your reving up and down problem is caused by the aic its what controls the butterfly in your throttle body if its not functoining correctly the pcm cant tell how much air is comin into the tb and causes it to rev high and low
and nothing personal but lay off the attitude every one heres just trying to help you and your be a little snot ass